When you scan a barcode to download an application or a theme or to open website, after you scan the barcode, your BlackBerry Browser should open to the particular page for the download or the website.

Do you have a BlackBerry Data Plan from your carrier?
Is the code that you scanned compatible with your device and your device OS version?

No one can "get [your] info off [your] phone" when you scan a barcode.

There are applications that will scan barcodes. But usually the scanner in BBM works for installing apps and opening websites.